This allele was generated by breeding mice heterozygous for Evx1tm1Gld and transgenic mice expressing cre with a protamine promoter. Expression of cre excised the portion of the homeodomain encoded by exon 3 and a neo gene, leaving IRES-tau-myc in the 3' untranslated region. Analysis of transverse sections of heterozygous mutant embyros showed that the expression of tau-myc resembled that of the endogenous gene. (J:70192)